Originally Posted by Rabbit

I don't agree. Time and distance are indeed far bigger problems than any erroneous assumptions we may make about aliens.

Do we?

That is a reasonable assumption. If they don't have long distance communication and/or space travel, we're not going to meet them. Long distance communication can't be done by smoke signals and spaceships can't get very far on steam engines.

No, we wouldn't be able to talk to them if they were less advanced because they wouldn't have radio. If they were more advanced, they would attempt the simplest form of communication that an alien (we) could receive, i.e. radio.

Really? There is a school of thought that says any civilization that is advanced enough for interstellar travel must have had the potential for self-destruction and avoided it, but I haven't heard any consensus based on that in regard to how colonists would behave towards the inhabitants of worlds they wanted. Some people think they'd be peaceful, some think they'd be dangerous.

Actually, most of them are quite reasonable.

Neither is there any particular reason to assume they will be hostile.

Doesn't matter. SETI does not assume that ET's visible spectrum is the same as ours and it wouldn't make any difference if they did. Their methods are based on simple principles which would be obvious to any creature intelligent enough to embark on a similar project.

Since we're not going to attempt to open a discussion with ET using sound or visible light, the point is moot. The frequencies used are chosen for a glaringly obvious reason that applies equally to any sufficiently advanced person in the known universe who wishes to communicate. I'll spare you the details, but there are some very convenient and very obvious (to any race with some knowledge of the radio sky) "holes" in the radio noise of the galaxy. Using the so-called "water-hole" wavelengths would be so obvious to anyone wishing to search for intelligent signals, it wouldn't occur to them to use anything else.

Which is why we wouldn't attempt to open communications with a television picture. First contact has to be a simple message that only tells the receiver "I am intelligent and I want to communicate" and there is a very easy way to do that.

We're not going to be able to talk to, or even find, anyone who hasn't developed radio; that's a no-brainer. As for talking to someone more advanced, they can't possibly miss us if they happen to look in the right direction at the right time. Whether they still routinely use radio for communication or not, we'll stick out like a sore thumb to an alien astronomer and it'll take him about two seconds to realise that the source of the radio anomoly (we are the brightest radio object in the sky for several thousand light years) is artificial.

You have been misinformed.

They don't have to be great codebreakers because we're not going to attempt to communicate in English. There is a universal language that any receiver will recognise as unmistakably intelligent and that language is mathematics. As I said earlier, the initial contact only has to inform the listener that someone wants to communicate, and that can be done by simply transmitting a repeating series of prime numbers - something that can't possibly be accidental. After that, you don't have to be a great cryptologist to understand someone who wants to be understood and the next thing you send, or listen for, because it's obvious and logical, is a set of numbers defining the two dimensional matrix on which you will draw simple pictures. It's not as difficult as trying to break the code of someone who is trying to transmit secrets, it's a two way development process between people who want to be understood and keep the logic simple.

Nobody is looking for pre-industrial races and nobody has suggested that anyone should.

You are assuming that someone who doesn't use radio for communication won't use it for anything else. If "they" are interested in outer space, they most definitely will have use of radio technology because the entire electromagnetic spectrum is, and always will be, essential to astronomy and any signal that is designed to be interpreted as artificial will instantly be recognised as such by anyone who receives it.

Agreed, but not for the reasons you think. Sound and light didn't develop to be of use to life forms, life forms developed to take advantage of sound and light. Life on other worlds will develop to take advantage of conditions, and if we assume that a nearby star and some kind of atmosphere are minumum requirements for life, then they will be able to see and hear. But it's irrelevant, becaise we're not going to try to make first contact by means of sight or sound, we're going to do it by numbers on the radio.

What? How does their social structure have any bearing? Either they're astronomers or they're not. If they're not, we've got no chance. If they are, their social structure is completely beside the point - if they look in the right direction at the right time, they'll see us. Their level of technology is irrelevant provided they are least capable of radio astronomy.

The motives of technology do not alter the fact that the methodologies are determined by the laws of physics, which are universal for at least as far as we can see.

No, the most likely outcome is that we'll have a lot of very slow two way conversations with someone who doesn't know how to travel hundreds of light years in a reasonable time.